Senior Python Engineer for IBKR Algorithmic Trading System

Marcus Engine Technologies is building an existing Python-based market-analysis and trade-execution system. The repository is active, extensively tested, and already has a working read-only connection to Interactive Brokers Paper through IB Gateway. We need a strong hands-on engineer to help move the system from its current Paper integration toward a dependable end-to-end product. This is not a greenfield project, a strategy-selling opportunity, or a request to build a generic trading bot. You will work within an existing private GitHub repository, understand the current architecture, and take ownership of useful implementation work. Initial engagement: * 10–20 hours per week * Initial paid trial of approximately 6–10 hours * Potential continuation for 1–3 months or longer if the relationship is productive * Work through a separate Git branch and pull requests * Coordinate directly with the Founder and an AI-assisted engineering workflow Likely responsibilities: * Extend and harden Python integration with the official Interactive Brokers TWS API and IB Gateway * Work with asynchronous/event-driven broker callbacks * Improve order lifecycle handling, reconciliation, recovery, containment, and execution safety * Integrate market data, orchestration, monitoring, or user-facing workflows * Diagnose real defects and implement tested corrections * Write and maintain pytest coverage * Run focused and complete test suites * Explain technical findings clearly to a non-programmer Founder * Deliver working code rather than lengthy speculative documents Required experience: * Strong production Python * Git and GitHub pull-request workflows * Automated testing with pytest * Event-driven or asynchronous systems * External API integration * State machines, durable state, and failure recovery * Clear written and spoken English * Ability to understand an existing codebase before changing it Strongly preferred: * Direct Interactive Brokers TWS API or IB Gateway experience * Algorithmic-trading execution systems * Order states, partial fills, cancellations, broker callbacks, and reconciliation * SQLite or PostgreSQL * Windows development environments * Real-time market-data systems Important boundaries: * Initial work is offline and Paper-focused. * No access to live capital or broker credentials will be provided. * No direct changes to the main branch. * We are not seeking guaranteed returns, trading signals, MetaTrader indicators, Pine Script conversion, or a complete rewrite. * Existing safety controls must not be weakened merely to make tests pass. Paid trial: The selected candidate will receive read-only access to the private repository, establish the project locally, run the tests, explain the relevant architecture, and complete one bounded real engineering task on a separate branch. The trial is paid. Successful delivery may lead immediately to continuing subsystem ownership. When applying, answer these questions: 1. Describe one system you personally built using the Interactive Brokers API. Which callbacks, order states, and failure cases did you handle? 2. How would you prevent duplicate callbacks, reconnects, or partial fills from corrupting order state? 3. Provide a GitHub link or describe a production Python system you personally implemented and tested. 4. Confirm your weekly availability and your proposed hourly rate. 5. Confirm that you are comfortable improving an existing architecture rather than replacing it. Please distinguish clearly between work you personally performed and work completed by a team.